Clearance pocket



May 25 1926. l,586,278

w. c. BARDENHEUER CLEARANCE POCKET Filed June 27, 1925 3 Sheets-Sheet l jfzaa72r afi rdezgzquer; wwg g May 2s 192s. 1,586,278

W. C. BARDENHEUER CLEARANCE POCKET Filed June 27, 25 s sheets-sheet z III a; I fiverzz ar" 49 Ji ZZZzzm afimzerz/Zeuaz May 25 1926. 1,586,278

w. c. BARDENHEUER CLEARANCE POCKET Filed June 27, 1925 I5 Sheets-Shoot :5

jYp'ZZZZzm afipqwkrz%eaerj Patented May 25 1926.

UNITED STATES 1,586,278 PATENT OFFICE.

WILLIAM G. BARDENHEU'ER, OF CHICAGO, ILLINOIS, ASSIGNOR TO BRUNSWICK- KROESCHELL COMPANY, A. CORPORATION OF NEW JERSEY.

CLEARANCE POCKET.

Application filed June 27, 1925. Serial No. 38,989.

This invention relates to improvements in clearance pockets, and more especially to a clearance pocket provided with means for varying the effective size thereof.

My improved clearance pocket can be easily and cheaply made, is strong and rugged in construction, and is so made that the effective size thereof can be easily and quickly varied without removal of the pocket. The clearance pockets of the type here shown are adapted for use, for example, in connection with pumps and compressors such as, for example, an ice machine compressor. Such compressors, as is well known, operate to compress the gas used in connection with refrigerating apparatus such as, for example, carbon dioxide, ammonia and the like.

Such a compressor as is ordinarily used in refrigeratin machinery comprises primarily a cylin er with a reciprocating piston therein and the usualinlets, outlets, valves and the like. In such a compressor there is ordinarily a fixed stroke. If it is desired, therefore, to vary the capacity of the compressor and consequently the power required to operate it, it is necessary to change the speed of the compressor unless other means are provided. ,As such compressors are frequently run by synchronous electric motors it is frequently difiicult to vary the speed, and consequently it is desired to provide other means to vary the capacity of the compressor without changing the speed. By the use of my improved clearance pocket this canbe accomplished.

In general, my improved clearance pocket operates to change or vary the effective size of the space remaining in the end of the cylinder at the extreme end of the stroke of the piston. In other words, the pocket operates virtually to change the clearance of the piston and hence is referred to as a clearance pocket.

Other features and advantages of my invention will appear more fully as I proceed with my specification.

In that form of device embodying the features of my invention, shown in the accompanying drawings, Figure 1 is a vertical sectional view of the ordinary type of compressor showing two of my clearance pockets in place, Fig. 2 is a vertical sectional view of one of the clearance pockets, Fig. 3 is a view taken as indicated by the line 3 of Fig. 2,

Fig. 4 is a View taken as indicated by the line 4 of Fig. 2, and Fig. 5 is a vertical sectional view of a modified form of clearance pockets.

As shown in the drawings, 10 indicates in general the cylinder of the compressor with a piston 11 reciprocating therein. 12 and 13 indicate the usual ports at the ends of the cylinder of the compressor, and 14 the port in the center. 15 indicates a cylinder head. These parts of the compressor are of the ordinary type, forming no part of the resent invention, and consequently are not described more in detail herein.

16 indicates in general one of the clearance I pockets in its entirety at one end of the cylinder of the compressor. Since the pockets are similar to each other, I will describe in detail but one.

The pocket 16 comprises a cylinder shell 17 open at the bottom and fastened to the cylinder 10 in any convenient manner such as, for example, by the cap-screws 18. 19 indicates a port or passage 1n the end of the cylinder 10 communicating with the end of t e bore thereof. The port 19 at its outer end is slightly enlarged and provided with internal threads as indicated at 20. Outside of the threads 20 there is a further enlargement indicated by 21 and beyond this three further enlargements indicated by 22, 23 and 24. The resulting shoulders formed by each of these enlargements are indicated b 20", 21., 22, 23 and 24, respectively as s own.

Threaded into the threaded portion 20 is a bearing piece 25 having its lower end seated on a gasket 26 resting on the shoulder 20". The bearing piece 25 is also provided with an enlargement forming a shoulder adapted to rest on the gasket 27 lying on the shoulder 21. The bearing piece 25 is also provided with a shoulder 28 substantially level with the shoulder 22 and resting on these two shoulders is a. gasket 29 provided with holes 30 therethrough. The upper end of the bearing piece 25 is provided with a circular recess 31 serving as the bearing for I the lower end 32 of the threaded shaft 33 extending upwardly through the pocket.

ill]

dicated by 36 in order to permit turning thereof by a wrench.

Within the shell 17 is a piston 37 provided with a groove at one side fitting over the feather 38 to prevent turning of the piston in the pocket. The shaft 33 is threaded through the piston so that turning of the shaft operates to raise or lower the piston in the pocket. The piston is provided with a circular flange 39 adapted to rest on the gasket 29 when the piston is in its lowermost position. The bearing piece is provided with a centrally arranged passage i communicating with the port 19 at its lower end.

The upper end of the passage a0 is provided with two lateral openings il leading to the space above the shoulder 21 and below the gasket 29.

42 indicates aslziet resting on the shoulder on which e lower edge of the shell 17 tests order t tight joint between "he clearance pocket and the cylinder 10.

it indicates rupture plate of ordinary cons action adapted give away in the event of undn A ressure in the upper end of the clearance pocket.

indicates check valve of any suitable construction in the piston 37 adapted to permit drainage of fluids theretlirough or the escape of undue pressure in the pocket above the 37.

The operation of the device is as follows: With the piston in the position shown in Fig. 2, the pocket is set to give its minimum clearance. When thus set, the gas compressed in the end of the compressor cylinder cannot go beyond the gasket 29 which has the flange 39 of the piston 37 resting upon it. In the event it is desired to increase the clearance of-the compressor, the shaft 33 is rotated to raise the piston 37. This raises the flange 39 from the gasket 29 so that gas can pass through the holes in the gasket 29 into the clearance pocket in the space below the piston 37. Such gas, however, cannot pass above the piston 37. Consequently, the efi'ectivc size of the clearance pocket is only the space below the piston. By rotation of the shaft 33, the piston can be raised as desired, in order to increase the effective size of the ocket.

Any suita 1e means may be provided in order to show from the outside of thedevice the position of the piston therein. For example, I have shown as such means, an indicator dial 455 provided with indicia 46. Below the dial 45 is rotatably mounted a toothed wheel 47 carrying an indicator 48. The wheel 47 is turned by a small toothed pinion 49 on a counter-shaft 50 which in turn is rotated by a wheel 51 provided with pins 52 adapted to be engaged by an arm 53 on the shaft 33 upon rotation of the same. It will be seen that rotation of the shaft 33 will thus be recorded by the position of the indicator hand d8 on the dial 45 so that there will always be shown the number of rotations that the shaft 33 has made and, consequently, the position of the piston 37 inside of the clearance pocket.

Tn Fig. 5 T have shown a modified form of the device. In describing this device I will confine my attention to pointing out the differences in construction between this clear ance pocket and the other. It is to be understood that where such differences are not pointed out the construction in general is the same as the other pocket. Also, in describing this pocket I will use reference numerals with a prime to indicate parts similar to those in the preferred form having siinilar reference numerals without the prime.

In the modified form, the formation of the outer end the port 19 leading to the interior of the cylinder is somewhat diff The outer end of this port 19 is ened as indicated at 20 but this enlargement is not threaded. The upper end o the enlargement 20 is beveled as indicated by 54 in order to form a seat for the valvedisk 55 rotatably mounted on the end of the shaft 56. Above the seat 5 1, the port 19 is beveled outwardly and considerably enlarged, 24. indicating the final enlargement thereof. 2% indicates the shoulder formed by the enlargement 2d and on this shoulder rests a gasket 42 on which the lower edge of the clearance pocket rests in order to make a tight joint with the cylinder.

33 indicates a rotatably mounted threaded shaft passing through the clearance pocket on which is threaded a piston 37. The lower end 57 of the hollow shaft 33 is provided with a bearing in the spider 58 which rests on the gasket 42' and is held in place by a shoulder 59 formed in the lower edge of the shell 17 of the clearance pocket. The shaft 56 is rotatably and slidably mounted in the hollow shaft 33, its lower end being threaded as indicated by 60 in the lower end 61 of the hollow shaft 33.

The valve-disk 55 is rotatably mounted on the end of the shaft 56 but moves upwardly and downwardly therewith. It is held on the end of the shaft by means of two pins 62 lying in the annular groove 63 on the end of the shaft.

64: indicates a handle adapted to turn the hollow shaft 33, and the upper end of the inner shaft 56 is squared, as indicated by 65 in order to permit turning thereof by means of a wrench.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may. be'made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention 'as:

i said shell, a threaded shaft extending said through said piston, and a bearing member adapted to support one end of said shaft, the other end of said shaft projecting outside of said shell, whereby said shaft may ,be rotated to move said pistonin said shell.

2. In combination with a cylinder having a reciprocating piston therein; a clearance pocket attached to one end of'the cylinder comprisinga substantially cylindrical shell; a port in the cylinder wall affording a communication between one end of the bore of the cylinder and the interior of said shell; and means for varying the efl'ective size of said shell, said means including a piston in said shell, a threaded shaft extending through said piston, and a bearing member mounted in the cylinder wall adapted to support one end of said shaft, the other end of said shaft projecting outside of said shell, whereby said shaft may be rotated to move iston in said shell.

3. n combination with a cylinder having a reciprocating piston therein; a clearance pocket attached to one end of the cylinder comprising a substantially cylindrical shell; 9. port in the cylinder wall affording a communication between one end of the bore of the cylinder and the interior of said shell;

means for varyingthe efi'ective size of said shell, said means including a movable piston in said shell; and means for closing said port near its inner end, said means including a depending circular fiange on said piston.

4. In combination with a cylinder having a reciprocating piston therein; a clearance pocket attached to one end ofthe cylinder comprising a substantially cylindrical shell; a port in the cylinder wall leading to one end of the bore in the cylinder; a movable piston in said shell; a threaded shaft extending through said piston and having one end projecting outside of said shell; a bearing member mounted in the port in the cylinder wall, said bearing'member supporting the other end of said shaft; and a port through said bearing member afiord- 'nder wall and the interior of said shell,

-ingla communication between the port in the thereby establishing a communication between the interior of said shell and one end of the bore of said cylinder.

' 5. In combination with a cylinder hav ing a reciprocating piston therein; a clearance pocket attached to one end of the cylinder comprising a substantially cylindrical shell; a port in the cylinder wall leading to one end of the bore in the cylinder; a movable piston in said shell; a threaded shaft extending through said piston and having one end projecting outside of said shell; a bearing member mounted in the port intheocylinder wall, said bearing member supporting the other end of said shaft;

a port through said bearing member aifording a communication between the port in the cylinder wall and the interior of said shell, thereby establishing a communication between the interior of said shell and one end of the bore of said cylinder; and means for closing said communication between the cylinder bore and the shell at a point just beyond said bearing member.

6. In combination with a cylinder having a reciprocating piston'therein; a clearance pocket attached to one end of the cylinder comprising a substantially cylindrical shell; a port in the cylinder wall leading to one end of the bore in the cylinder; 'a movable piston in said shell; a threaded shaft extending through said piston and having one end projecting outside of said shell; a bearing member mounted in the port in the cylinder wall, said bearing member supporting the other end of said shaft; a port through said bearing member affording a communication between the port in the cylinder wall and the interiorv of said shell, thereby establishing a communication between the interior of 881d. shell and one end of the bore of said cylinder; and means for closing said communication between the cylinder bore and the shell at a point just beyond said bearing member, said means including a part on the piston adapted to so close said communication upon movement of said piston to its lowest position. I j

7 In combination with a cylinder having a reciprocating piston therein; a clearance pocket attached to one end of the cylinder comprising a substantially cylindrical shell;

ton in said shell; and means for closing said port near its inner end, said means including a part on said piston.

In testimony whereof I have hereunto set my hand and seal this 25th day of June,

WILLIAM C. BARDENHEUER- 

